The ready to use and versatile ClearGuard Pressurized filter is designed to be both functional and user friendly. The unit can be buried up to the ring clamp to make the unit easy to disguise in the landscape. Includes a built-in 7-way valve to switch the unit between its various functions: Filter - water passes through media in filter drum and back up through the UV/clean water chamber and to output, Rinse - water flows though valve and exits through waste port to clean away dirt in valve after a backwash cycle, Circulate (bypass) - water passes through the valve without being filtered which is useful during times of medication where moving water is still needed, Backwash - water runs reverse through the clean water area then filter media dislodging debris and then flushing it out the waste port, Closed - this position closes off the intake to the valve and is used to temporarily shut-off the valve to service the pump, Empty (drain) - water enters the intake and goes directly to the waste port which is useful for draining the pond, Winter - this is a neutral position that equalizes pressure through all three ports when the filter is shut down for the winter. Filter is available in 4 sizes both with and without a UV clarifier to filter ponds up to 16,000 gallons. UV Clarifier models include one UV Clarifier with the ability to add an optional UV in the Unit includes all fittings for flexible or rigid tubing installations. A submersible or external pump and tubing (both not included) is necessary to operate the ClearGuard pressurized canister filter.